SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '802bc64528936cece05274d2bb0d1c1d5cf0d7fb5f6ba23b3f3935d35a93acef' 
  AND token = '3gJ3oLkpP4Gy/wuk5AvEuifPNLkabGoaaMQe4puUoDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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