SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b70cab963a6980b26ea1d15fbff3bac06adbd0a295872ccaf4ff0b3f981accbf' 
  AND token = 'YWaRNTTYCdz0ViJOo4lYDSiy2mbau8yQXmzGQ5FbnIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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