SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '6fbae7f45663b77673f3afbdc1daf147efff3461a5f6291606691278937dbe22' 
  AND token = 'R+jfesjcEs5RST9e5Ln3QsudnCCePRuK5mxfmG0wtwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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