SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82b949ca5984b9e89474f9c6ab4d034f19b7bc115bb5d45a63fdfce88a9ab372' 
  AND token = 'JwSWUdNAzDBoJpA1BT07bkEE15vaEaxXc05hUhH2wPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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