SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '212a0f49bef8d6b0e1ef64bdec143abcf111b689ee07dc3bcfca88fbdf28a5ed' 
  AND token = 'IitOSs1favCfJ/00SuIasc28cLBxMqI5XXq0kYAjNvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}