SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2009c05e6463993fa8fdae259f9540505db0b142bc1c50fef41a0307193f2c1f' 
  AND token = 'riOWvcJMFd1Kg6aI5SlZLyTCXdbpr2EWjXFoW+VNLTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}