SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea46ebfcc98ef548446399f51211f91a27117f32425f64ff9b85907e28e80c71' 
  AND token = 'GXRzMZ1RhRJi8MMmSw+xPZkpRT6oDLYc7srRnYW6cfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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