SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ae0e17c16d0bfe71c1baa6b4d2eeebdc06a056c389192d3392026699d2af041' 
  AND token = 'AVAVq/kuR58vCjLY+rbBoh4rXVaZCUWlUgxPp2Lf7Tw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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