SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a83335b77d5b4a8232e4927b02d9089c2bc9f4067fbb0904c9c48e0252b55e1' 
  AND token = 'S7H5UMC1e/XjSDkUwZX1WqPdGbBIFD+kI9vTwRXYbTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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