SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8c8935ebe7d109e76696555240d0b6ddfa7d6d071b8f13b2e7ebc6c60c0d785b' 
  AND token = 'FELJqqIJEquONLHPhg1fHr0DqwRs09DQpKNCNp39IB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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