SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f361e6042393ba7b7586cfea9c90c04fa32ef9088afb06302c96755b22bd8ac' 
  AND token = 'PDb7ckJC0LsD1fTuPjcrWtODSvYodtci0RkyaFcvkIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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