SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f6bbfd0bbe924f4a5b596c9e1c097602abec513aac6267b1a4dd215f7688a73' 
  AND token = 'Pce5+aKkfKontFF0ohdhwiIIyEtTynoihk8i/Cxa0iQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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