SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b253fb679627a9b1b93d12a0c2f4bfeed644e204efc763bab1b9be3df8554821' 
  AND token = 'gBCQHtnYTy/vBqmHvxMzZmUuR8PLUCyUcgtf+OEs+tw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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