SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25ce901dc99dfcb373960b87f9f4ece0684c6b63387bacdfa98a5455d696bf44' 
  AND token = 'EOjMgTYmLKV4JGEWVoqoFf0D+05KpqrKgslI27gNxUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}