SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a5d7c71d44fe7fea34dda75a1b703ecc82225f3d3a7779b91f93c6d25930c18c' 
  AND token = 'Rwpcg4aeUFpU15figMP7d1Yfl5dKxWpOh2a9hHAndgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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