SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '376ee8167fe0bd4c8baaf420000ad0aad021588e9dcfec53bf272dcb0bafeebd' 
  AND token = 'IaawcnrBI3DSLb9+IRvmLkRdUMzcZ9bKuKoBDMbRhW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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