SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'beeeac1a0db95bf07cceab9b714750c1131e09a7d80faf9c686bb748d861ad26' 
  AND token = 'hcnFcgGuLzcm7fXtuIrTlTKv8cTVSBXUGDalvPDNxvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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