SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28774e5bbfe11d9dd28d8b56ef045b02450f0db2f0754b84addcef961d2f6c5b' 
  AND token = 'Nv+Pip9FEPYy3czC1k+2bTYfbf7vNZcvcgxvwEK5fNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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