SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e739be5cc496f32f146ee47f4a1bef5cccd1f4dac320fce96e3d34a124624765' 
  AND token = 'YrRjUw8CPzVobZkrxIeH3Nrj4m22ZejGVo+BsYPuNO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}