SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b505bfb4a46ddc06e94303b2063d8c53c5f83d605669fbcc97b9424904ade4a6' 
  AND token = 'V0BpTgGFx9OB+X99L1ganUw2YorFQ3pxNUsVgqHArxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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