SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfd8d43d4b71eb95a1937860c6e2468bdf679abdfd514c297b18354124cce620' 
  AND token = 'kXURtkMwOE4NtMkaJSKjvF2f207DDlu802y8CCSiWV8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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