SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd29d8d4c6a684ed460181d38b625f28eb86cffbfacdaed291ff58f809e3aec5' 
  AND token = 'u6mX4QIKy4ThS1d30UFCq3Ut58mvXpBoOfNbWR3fYo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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