SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a0c1487224b36934a69da1047037656246f2680c9ad2af0ce8c66df2391b79c' 
  AND token = 'zoJZwm3aBmngrkwKqBAxjIZwmFf7vAHdLBwltZ4ZK4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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