SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1d1c150de27ff63982723c93d81f0e71eb7454cd1a9bf1d9282ce9537798757' 
  AND token = 'lfs9er2nNgokCJ7F17cdP9vCgvZzjM6WiJp+veCoICU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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