SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e072c0a9e1f0dc92e0287d23132ce9d51cf32f4304230dea7882e383aa479c30' 
  AND token = 'aUsOQ8GuUG2B3FrTWCipXjQYtLnuMAu+BuH4gEfpGR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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