SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1a61a6a2c4315f2510914392e3d473d832b65da84269472d3447477c65436de' 
  AND token = '+U3aqvtrcepQylj3Vcsv+YRFbdYBgXpVJChdCBTNEPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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