SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa13d0b67b609216c4f00fff801084713f11b64c1beba614ad2dd1f44c52a996' 
  AND token = 'gOcFsHsFU2/g+Ck2wmmQNuvnXVOWmhFTnfvF7wjDWsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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