SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4c0b0c4c467af8d74a31917cfaf374dbb4676fffdfc20d8bf3227376720a3b2f' 
  AND token = 'rUaioYPrpGjGiAJ1mdTHV7J3rJPfKJbB8Tc907p8pmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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