SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66817a385ad8981c72e693a1e3ab5abd61a6fb9319a47c19fe4b29093e03e0c7' 
  AND token = 'cE5nhhGbryK3KlzcJbzJHse0fAUM/W4tA/Q2oD6FxBQ=' 
  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"
    }
  }
}