SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e02bc4eaf0db96ec583ce526c858826940ef690a09799e8d58b3fea1ed96eb25' 
  AND token = '7NX8A7WY493ShmxLuy1s3k2sOOv7PXT1ouqT5ecQZFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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