SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb10c9884ef68a445c066479e413b943ccf596ca400573a21bfbcafb429544a5' 
  AND token = 'qD37pIigmvLEos0OjGGxbKTQDvQBYZ2bc37PZdCa9hc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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