SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7d4688829619b822437300e9e316a528a7b223a427c9b03d408508c6e29835e9' 
  AND token = 'Uwy7N0Ol6wL+e5HUzz30yo+AsHsynciHVoz0k76pwzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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