SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac0c97910097d61ec9fe6be3a3413449e604bc1985dd90688d8ec970be63bfcb' 
  AND token = 'XDt1wDyLfg9fSzMNCWFFjoA6OnjicOTXlqAbJe6v/gU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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