SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '927880f879515493b24339ed87114ffbc3ee40f38bc7001aac6d977ca6a58190' 
  AND token = 'QDbuo3E0oLGha1/xBpO90EyUoQUMOoSMDOJw/C7aIt0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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