SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '252d5616c12f0084a4c30a046a52506e299d5b1bc5558288cf0b636acddd01f0' 
  AND token = 'lXRjGYBTPMAbnmmsBR/S2BIokkvFpc29jrI8srWmdro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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