SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e86e7888db7611da6a84d121128ef1585b4242413f55de71718f087125803d8' 
  AND token = 'pjKltRUnTnXnmidBownyPbOdMF879ix6DP6/hvmXKcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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