SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0642c16bd0094cecd31f5de4ed16220b81f55814e008f636330c72533512b00' 
  AND token = '27mdoX97wSSGA0fbzo8H/RtLHYFYZcLgBfSHBqfzzW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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