SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d40fcc2d967a12e12ea188203db8379af09c2909af07605d534be53dab033e0' 
  AND token = 'rhjLfr3Xsej7DhtKrkwzYZZLz3Pv68rq4JA6iUgGSVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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