SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09e3879d84b686be54fc2ae58885a0da52830fedca350d54e7f8827d18a18d0d' 
  AND token = '/MKYwQlUUhOUTp7KhQcsMgw09Y2LB0NOeQblaCTJ/Dg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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