SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '1663b9b4b327c9f3a06461205fcae0e3ff68d2860faf6e452387acdf3af57897' 
  AND token = 'aiqLJFeiVWGcOlLSMdA8tUV6yjBPuYqeKS4GHBBK4NY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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