SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9045e8d9c98b09c2771846eba586d58e1107cbd7b5785e3220a717bd701aa6a1' 
  AND token = '2exqIjk+2RMQoBSPN9s5vuwYAGg0ffVNlTizAkbwP7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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