SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bc73c0e89e5d7592ee36c69ccee1429251b604e942296eadb293a61cb3390f03' 
  AND token = 'PuEJV/rEZnl+7zx2U3cySxdTBaSxe5oWfnMLlGTwuE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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