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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '85440d24dcacb6a3fef09be2678c27631f7f49a79a6a1c0910f6c826321a54b9' 
  AND token = '2xM1gBkj1vT7YIrvSK2AQESEo0NZxPNf9C7uJZMT9+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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