SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23bf8f90234792b552f8b1198badd26464c1dfd61443288d38683b6eb08f68a9' 
  AND token = 'U7NYJzwAhLs3GWsirFEct1Y3GyWOyAaxeCXjQwm3vhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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