SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8207f91aedb8f85dcaed41512f73a6e194e4fefddf5a042a34324c37fc64bcb5' 
  AND token = 'XvEOAJZHBSkcw3slUxjms6Cb018gyFT6bMvDNKJpsVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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