SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'bc26e501413330abf3a48e17d022933bdf33eae5aa262cf000b03390ee0f622c' 
  AND token = 'InhiDa2Q4ZUnvJ5mqoMrkSAxo8z82QlyV3z+BC/lLZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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