SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9209fe05bfb49d3074cf543bb38799917a8de71bc305ff08eee00e131c2c9d06' 
  AND token = 'zZMidNSjk3a0LHEqezDRsrgHlKCn9RI8gNfDTfB+HPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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