SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e2fd721742e39234dcc01ba7a460823f495e09adab85f120974420bdfc8a446d' 
  AND token = 'v6YavoDiYkEuNi9v2UpaYpG9XhvE6mQIzucWI+k1UWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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