SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e5840a7b3fd5d1ed0f142f1370d79c9b840f96e500be38997dfc506bfbe5854f' 
  AND token = 'eSf/B0FXhtMnwtAAkC91Re+zaj5kkMx855xNw7hGyns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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