SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c29eff146ef0bfa1fa4b8c10ff4114b4515f833294a44aae24e6f0ca1952916' 
  AND token = 'RX+/Yrop3a2u5uRsYZ58H02sPZwrsygIFZ8aardEpGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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