SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86c3ce7a75d2543e5d87bdc788b978c38c3e699c52077d4604c15b98340ff47c' 
  AND token = 'SwvBCIW1/EMJKzqtNhLFSdmnnQKDtcFQnfXPMAwxST8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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