SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bc38e05f203da7b0851792f5d7b7e2caf670371aabace3a0bdbd1e21ae8c37d' 
  AND token = 'FHfBgtl791nVCzUg0TL2ghmRGR7h9gl7aruY0Atb8cc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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