SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dd85bf48c6c57c9d60dc6bb9997c0f264b0c4a44497cc24b828937cb6050dc74' 
  AND token = 'uI/AqBo9z9wtC/q8Kzsp+iiqjQgu9fFZOoxhelTKZuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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