SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e8228330dcad6daaa1add49fa3909c6e563f25bad657b90143493b16380700d' 
  AND token = 'AtWDuvkgm9tVABJlr2iKI8uVSMHxJc/OZ7QKMz8GKJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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