SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9e7df164cec30bf2152cb4f28bd2c44e822361bfa07b054cb30d507062d6853' 
  AND token = 'mWmuxowtqd0qLmqEbxsB/OJEL9pRJExAtdFknYSXVGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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