SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3e27cf299f6e87d02f415734e9a26f25bd5ab70b07c77acccbf16a15b0be4b9b' 
  AND token = 'c+CcWI/LxPgPhmayBC9F7KZWCwtetdO0zHjUkQM+nLQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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