SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e436636a84e6e28ff1590410369f1ae9a0d670bb83befa9f0d515c60c86e8c8d' 
  AND token = 'fqGo4WccF4x5BD2CWJqzjhBROrQLBsYL3hMZyOwRgj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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