SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e166795114f7aad6ab5c32e702de9024ca6c816259162788f61e59b41470e226' 
  AND token = 'nEHwikdw74yS1NknneFjS2f4S39eqxyMGkLFCbFy6og=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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