SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43d72131ce037d73175b253b1b24dfd765b6700f04cbd4d41edf639212200c16' 
  AND token = 'yzstk1S+pJSYk5+FZOPEZNLYmHR0pRV9xhLJzVGg7Uo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00067

JSON explain

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