SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4db05bf5958cbaab4cb59a53f27146733a8aa7d2baf876b3d71c55e816d59c3f' 
  AND token = 'VVmGDKJQUb8JABbqbT2jP9azTxQ+kT+bhcewz11ZOpE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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